Scroll down and change APN protocol and APN roaming protocol to IPv4/IPv6.

Then change the Bearer to LTE.

Don’t modify any other settings and save it by tapping OK on top right corner of the screen.

Select the APN and reboot your smartphone.

Now all your 4G VoLTE issue for Jio will be resolved on Lenovo ZUK Z2 Plus.

Note: If even after performing the following steps you have any problem accessing 4G try changing the SIM from either SIM1 or SIM2. Also, make sure to select Jio SIM for the Internet and enable VoLTE hi-definition call in settings.